Modern electronic circuits and components may have quite high power densities. The interface between an electronic circuit or component, and a heat sink, should exhibit low thermal resistance so that heat can be conducted away from the circuit or component. One technique for achieving such low thermal resistance interfaces is the use of particle-filled adhesives or greases. Such adhesives and greases are also employed in other applications, for example, as electrical interfaces when the particles are electrically conductive or as mechanical bonds that may be enhanced by particles or fibers added to an adhesive matrix.
Co-assigned US Patent Publication 2005-0263879 of Michel et al., (now U.S. Pat. No. 7,748,440), discloses a patterned structure for a thermal interface. The Michel et al. invention provides a thermal interface with a first and a second face that are in contact to each other by a thermal conducting material. A first face includes grooves that are at least partly filled with the thermal conducting material, wherein at least two types of grooves are arranged, namely first grooves having a larger width than second grooves. The first face comprises an array with protrusions that are confined by the second grooves, the array being divided by the first grooves into sub-arrays.